The present invention relates to the use of a cutting cylinder unit for cutting a plant, the cutting cylinder unit comprising:                a cutting cylinder having a surface of revolution which is rotationally symmetrical with respect to a cylinder centre axis and having cutting members provided along the said surface of revolution;        a cylinder drive for driving the cutting cylinder in rotation about the cylinder centre axis;        a cutting edge which is provided along the outside of the surface of revolution for interacting in a cutting manner with the cutting members.        
Cutting cylinder units of this type are known from cylinder mowers for mowing grass, a ground-covering plant. An example of such a unit which may be mentioned is NL-80.04241. The mowing device described in this document comprises a tractor provided with a number of, in this case four, cutting cylinder units. Each cutting cylinder unit comprises a cutting cylinder which is driven in rotation about a cylinder centre axis and has a cylindrical outer surface of revolution, a cylinder drive for driving the cutting cylinder in rotation, and a straight cutting edge which runs along the cylindrical surface of revolution. The cutting cylinder is provided with knife edges which are provided at relatively large intervals with respect to the cylinder centre axis, running helically along the inside of the cylindrical surface of revolution, and on the cutting members. The cutting edge is provided along the cylindrical surface of revolution in such a manner that it interacts in a cutting manner with the cutting members or at least the knife edges thereof which move past the cutting edge during rotation. Elsewhere, grass can be mowed using a cutting cylinder of this type. Known cylinder mowers of this type are only intended for cutting a ground-covering plant, such as grass, in a straight line and are eminently suitable for producing very flat lawns.
It is known to cut various plants, such as boxwood bushes but also hedges more generally and also other shrubs, such as yew, privet, etc., or trees, such as a bonsai tree, into a shape. This work is generally performed by hand. With the aid of a cutting device, such as hedge-clippers, the plant in question is cut into the desired shape. This is a time-consuming operation. Particularly for certain types of plants which are sold to distributors or purchasers by the cultivator after they have been cut into shape, this leads to labour-intensive work which takes up a relatively large amount of time.